Allow tabbing from title to subtitle and subtitle to post content.

[kopepasah]

When working on a new post, the expected result is to tab from the post title to the subtitle and from the subtitle to the post content.

The current state skips over the subtitle input entirely (when tabbing from the title) and tabs to the buttons (when in text editing mode).

[philiparthurmoore]

I was wondering when someone would find this. 😃

I'll try to figure this out very soon.

[kopepasah]

Actually, I already have a fix. I'll submit a pull request soon.

[philiparthurmoore]

Woot! Excellent.